Thomas carrigg



(No Model.)

T. OARRIGG. DRILL.

No. 583,358. Patented May 25,1897.

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UNITED STATES PATENT Qrrrcn.

THOMAS CARRIGG, OF IVALKERS MILLS, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TOPATRICK FEENEY, ()F SAME PLACE.

DRILL.

SPEltFICATION forming part of Letters Patent N 0. 583,358, dated May 25,1897.

Application fil d December 12, 1895. $erial N0- 571,900. (No model.)

To an whom it may concern Be it known that I, THOMAS OARRIGG, acitizenof the United States of America, residing at lValkers Mills, in thecounty of Allegheny and State of Pennsylvania, have invented certain newand useful Improvements in Drills, of which the following is aspecification, reference being had to the accompanying drawings.

This invention relates to certain new and useful improvements in drillsin general, and relates more particularly to that class known aschurn-drills, used for drilling in rock and the like, although my formof construction may be used in makingabit for apowerdrill or as ahammer-drill.

The invention has for its object to construct a drill of theabove-referred-to class whereby a perfectly round hole may be made,which is not obtainable with the ordinary forms of construction.

A further object of my invention is to provide a drill of theabove-referred-to class that will be more easily operated than theordinary construction, inasmuch as it will not be as liable to bind inthe hole.

A further object of my invention is to construct a drill as abovedescribed that will be extremely simple in its construction, strong,durable, effectual in its operation, and comparatively inexpensive tomanufacture.

With the above and other objects in view the invention finally consistsin the novel construction and arrangement to be hereinafter moreparticularly described and specifically pointed out in the claim.

In describing the invention in detail reference is had to theaccompanying drawings, forming a part of this speoificatiomand whereinlike letters of reference indicate similar parts throughout thedifferent views, in which- Figure l is a front elevation of my improveddrill, Fig. 2 is a side elevation of same. Fig. 3 is a top view of same.

In the drawings, a represents the body or handle portion of the drill,which is divided or serrated on its lower end, thus forming lips I) b.The ends of these lips or jaws are rounded in a semicircular shape andsharpened on their edges, as shown in figures of the drawings. At thebase of the V-shaped opening formed by the lips or jaws are grooves c c,which extend a short distance into the metal.

My improved drill is operated in the usual manner.

The drill is lifted upward and plunged downward into the rock or othermaterial it is being used upon. As the bits or jaws cut the hole intothe rock the drill is revolved in the hands, thus bringing the bits orjaws on the opposite side of the drill-hole from that on which theydescended at the preceding stroke. As this operation is continuedthroughout the operation of cutting the drillhole, a perfectly roundhole will be formed by reason of the shape of the bits or jaws. Thisshape of the bits or jaws will also make the drill easy to operate, asit will allow of the same to be turned easilyin the drill-hole, and theshape of the jaws will cause them to cut rapidly into the rock by reasonof the faces of the bits or jaws being beveled and the formation of thegrooves c 0 allowing the chipped pieces of rock to be forced readily outof the way of the cutting edges of the bits or jaws. This will bereadily apparent by reference to the drawings, as it will be noted thatby this construction a larger space is formed for the chipped orcut-away portions.

It will be noted that various changes may be made in the details ofconstruction of my improved drill without departing from the generalspirit of my invention, and I therefore do not wish to limit myself tothe specific construction as shown herein. For instance, some minorchanges might be desired should the drill be used for power-bits or as ahammer-drill.

Having fully described my invention, What the metal; the inner side ofeach cutting edge 10 I claim as new, and desire to secure by Lettersbeing slightly rounded, while its outer side or Patent, is

A drill having two rounded cutting edges, each of which is flared orwidest at its lower edge, the two edges extending in a line with eachother, but separated by a V-shaped groove which has its ends terminatedin short grooves c, which extend a short distance into face is near] yvertical, substantiallyas shown. In testimony whereof I affix mysignature in presence of two witnesses.

THOMAS OARRIGG.

\Vitnesses:

ALFRED M. XVILsoN, H. G. EVERT.

